Fever (Department meeting 2/4/24) Flashcards

1
Q

What is this stain?
How is it done?

A

Ziehl Neelson stain

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2
Q

What does acid fastness mean?
What substance in the cell wall in AFB is responsible is responsible for this property?
Name another bacterium with similar property.

A
  • Resistance to decolorization by acids during laboratory staining procedures
  • Mycolic acids (long chain fatty acids)
  • Nocardia
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3
Q

Describe the MRI sequences
Describe the abnormality

A
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4
Q

Describe the abnormality
Sputum, urine, stool, blood were negative for bacterial culture and AFB smear, what would you do next?
Name one additional test to confirmed the presence of Mycobacterium tuberculosis.

A

PCR

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5
Q
A

Bone marrow aspirate shows macrophages engulfing haemopoietic cells including eosinophils and erythroid precursors –> known as haemophagocytosis

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6
Q

FeverPancytopeniadLFTRaised ferritinRaised TG HypofibrinogenemiaHemophagocytosis

What is your dx?
What are the common triggers/ causes?

A

Hemophagocytic lymphohistiocytosis (HLH) / Macrophage activation syndrome (MAS)

Infections
Viral (EBV, CMV, HIV, hantaviruses, HEV, H5N1, SARS coronavirus)
Bacterial (mycoplasma pneumoniae, salmonella typhi, legionalla pneumophila, MTB, orientia tsutsugamushi)
Fungal (aspergillus, fusarium, talaromyces marneffei, cryptococcus neoformans)
Protozoal (toxoplasmosis, strongyloides stercoralis)
Malignancies
Autoimmune diseases

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7
Q

Microscopic appearance: mould form, characteristic conidial heads

A

Talaromyces marneffi (formerly known as penicillium marneffei) is a dimorphic fungi. Different forms at different temp (25 degrees is mould) at 37 degrees is yeast

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8
Q

BAL shows what

A

Cytological examination showed a larva of strongyloides

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9
Q

RF for strongyloides stercoralis?
Importance of eosinophilia?

A

Rhabtidiform larvae in the gut become infective filariform larvae that can penetrate either the intestinal mucosa or the skin of the perianal area, resulting in autoinfection.

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10
Q

58/M
AML post sibling HSCT
FLT3-ITD, DNMT3A
Ruxolitinib 10mg BD for 16 months for cGVHD
Concurrent immunosuppressants: nil
Comorbidities: cGVHD liver and mouth

Please comment on the CXR
What is next Ix?

A

Diffuse bilateral pulmonary infiltrates (increased pulmonary vasculature)
CT thorax

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11
Q

Comment on the CT images
Name 1 further Ix

A

Extensive patchy GGO (ground glass opacity) in bilateral lungs
FOB (fibreoptic bronchoscopy) with BAL (+ve for pneumocystic jirovecii on silver stain)

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12
Q

What stain and organism?

A

Cysts of pneumocystis jirovecii on silver stain from BAL

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13
Q

RF for pneumocystis jirovecii

A
  • AIDS
  • Haematological malignancies/HSCT
  • Isolated cases of pneumocystis pneumonia (PCP) and the use of ruxolitinib
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14
Q

What is workup?

A

CBC/ clotting profile/biochemistry
CXR
Blood/urine culture
CT brain

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15
Q

Comment on CT brain
What is next step?

A

Right occipital hypodense lesion
MRI brain

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16
Q

Describe the MRI brain (FLAIR)

A
17
Q

What is your ddx?
What would you do for definitive dx?

A

ddx
* Infection: bacterial (salad, ice cream = think listeriosis), parasitic (neurocysticercosis, toxoplasmosis, histoplasmosis), fungal (cryptococcus)
* Demyelinating/para-neoplastic
* Malignancies (lymphoma)

Open brain biopsy

18
Q

Multifocal T2W hyperintese lesions at bilateral cerebrael and cerebellar hemispheres, some of them show enhancement
Open brain biopsy histology shown below
What is dx?

A
19
Q

What is good antimicrobial coverage in patients with haematological malignancies?

A
  • TB prophylaxis in patients with evidence of prior TB infection: history, CXR, IGRA
  • Active stool surveillance in unexplained eosinophilia
  • PCP prophylaxis in all post HSCT patients taking ruxolitinib
  • Septrin prophylaxis in patients with +ve toxoplasma IgG Ab
20
Q

What does TB, talaromycosis (previously known as penicillium marneffei), strongyloidiasis, pneumocystosis and toxoplasmosis have in common apart from strongyloidiasis?

A

All of them are intracellular organisms (except strongyloidiasis) hence in immunocompromised state are more susceptible to infection.

21
Q

Describe the CXR

A

Left middle zone consolidation.
Miliary shadow in bilateral lungs.

Miliary TB